THE STATUS AND DISTRIBUTION OF CONTRA COSTA GOLDFIELDS IN SOLANO COUNTY, CALIFORNIA RESULTS OF CONTRA COSTA GOLDFIELD POPULATION MONITORING FOR 2006, 2007, 2008, AND 2009 SOLANO COUNTY, CALIFORNIA June 30, 2010 THE STATUS AND DISTRIBUTION OF CONTRA COSTA GOLDFIELDS IN SOLANO COUNTY, CALIFORNIA RESULTS OF CONTRA COSTA GOLDFIELD MONITORING, 2006-2009 SOLANO COUNTY, CALIFORNIA Submitted to: Solano County Water Agency Prepared by: LSA Associates, Inc. 157 Park Place Point Richmond, California 94801 (510) 236-6810 LSA Project No. SCD430, SCD0601, SWG0701, SWG0801, and SWG0901 June 30, 2010 LSA ASSOCIATES, INC. CONTRA COSTA GOLDFIELD POPULATION ASSESSMENT JUNE 2010 SOLANO COUNTY WATER AGENCY TABLE OF CONTENTS INTRODUCTION ........................................................................................................................................4 CONTRA COSTA GOLDFIELDS....................................................................................................5 GENERAL SITE CHARACTERISTICS...........................................................................................6 Barnfield...................................................................................................................................6 Director’s Guild .......................................................................................................................7 Goldfield Conservation Bank...................................................................................................7 Jehovah’s Witness Complex ....................................................................................................8 McCoy Basin............................................................................................................................8 Strassberger Industrial Park .....................................................................................................8 Noonan Ranch Conservation Bank ..........................................................................................9 METHODS .................................................................................................................................................10 POPULATION STUDIES................................................................................................................10 Field Surveys..........................................................................................................................10 Data Analysis .........................................................................................................................11 GENETIC STUDIES........................................................................................................................12 SEED BANK STUDY .....................................................................................................................13 Soil Cores...............................................................................................................................13 Removal Plots ........................................................................................................................14 DISTRIBUTION STUDY................................................................................................................14 RESULTS ...................................................................................................................................................18 POPULATION STUDIES................................................................................................................18 Density, Cover, Average Number of Flowers per Individual, Population Estimates, and Between Year Comparisons...................................................................................................18 Between Study Site Comparisons ..........................................................................................35 Analysis of Vegetation Data ..................................................................................................40 GENETIC STUDIES........................................................................................................................48 SEED BANK STUDY .....................................................................................................................48 Soil Cores...............................................................................................................................48 Removal Plots ........................................................................................................................50 DISTRIBUTION ..............................................................................................................................50 DISCUSSION.............................................................................................................................................53 POPULATION ESTIMATES ..........................................................................................................53 Population Estimate Methodology.........................................................................................53 Between Year Comparisons...................................................................................................54 Between Area Comparisons...................................................................................................56 Vegetation Data......................................................................................................................58 GENETIC STUDY...........................................................................................................................61 SEED BANK STUDY .....................................................................................................................62 DISTRIBUTION STUDY................................................................................................................63 IMPLICATIONS FOR CONSERVATION AND MANAGEMENT..............................................65 Avoidance and Minimization and Conservation Measures....................................................65 Restoration .............................................................................................................................67 Adaptive Management and Monitoring .................................................................................68 REFERENCES ...........................................................................................................................................70 ACKNOWLEDGEMENTS........................................................................................................................73 P:\SWG0801\Section 6\ContraCostaGoldfields\CCGF_Report_Final.doc i LSA ASSOCIATES, INC. CONTRA COSTA GOLDFIELD POPULATION ASSESSMENT JUNE 2010 SOLANO COUNTY WATER AGENCY Population Counts and Tissue Samples .................................................................................73 Collecting Tissue Samples for Genetic analysis ....................................................................73 Access to conduct Additional Surveys...................................................................................73 For Sharing information on CCG Surveys.............................................................................74 Assistance with Field Work ...................................................................................................74 REPORT PREPARATION.........................................................................................................................75 APPENDICES APPENDIX A: MAPS Map 1. Regional Location and distribution of Contra Costa Goldfields within Solano County. Map 2. Location of Study Sites. Map 3. Distribution of Contra Costa goldfields on the Barnfield study site. Map 4. Distribution of Contra Costa goldfields on the Director’s Guild study site. Map 5. Distribution of Contra Costa goldfields on the Goldfield Conservation Bank study site. Map 6. Distribution of Contra Costa goldfields on the McCoy Basin study site. Map 7. Distribution of Contra Costa goldfields on the Strassberger Industrial Park study site. Map 8. Distribution of Contra Costa goldfields on the Noonan Ranch Conservation Bank study site. Map 9. Area surveyed for Contra Costa goldfields, their distribution and current reserve areas. APPENDIX B. POPULATION STUDY SITE PHOTOS APPENDIX C. VEGETATION ANALYSIS PHOTOS APPENDIX D. POPULATION GENETIC ANALYSIS of LASTHENIA CONJUGENS (ASTERACEAE) (CONTRA COSTA GOLDFIELDS) POPULATIONS WITHIN SOLANO COUNTY, APPENDIX E. SEED BANK STUDY PHOTOS APPENDIX F. CCG HABITAT PHOTOS FIGURES Figure 1. CCG density per meter squared (A), percent cover per ¼ meter squared (B), and average number flowers per plant (C) on the Barnfield Property....................................................................20 Figure 2. CCG density per meter squared (A – PPAA and B - GAA), percent cover per ¼ meter squared (C - PPAA and D - GAA), and average flowers per plant (E) on the Director’s Guild Property. .....23 Figure 3. CCG density per meter squared on the GCB Study Site. ............................................................26 Figure 4. CCG percent cover per ¼ meter squared (A) and average number of flowers per plant (B) on the GCB Study Site. .................................................................................................................................27 Figure 5. CCG density per meter squared (A) percent cover per ¼ meter squared (B), and average number of flowers per plant (C) on the McCoy